'It might be extremely difficult for some chronically and severely mentally ill patients who require antipsychotic treatment to eat less and exercise more when their treatment increases appetite and produces fatigue and sedation, and their illnesses decrease motivation and limit social interactions and activities,' the investigators note.

To counteract these tendencies, Dr Angelo Tremblay, at Laval University in Quebec City and colleagues designed a behavioural weight control program that included a 90-minute class about proper nutrition and exercise, and a structured, supervised exercise programme. Sixty-minute exercise sessions held twice a week included cardiovascular workouts, strength training exercises, and flexibility and balance drills.

Dr Tremblay's group evaluated the programme in an 18-month trial among patients with schizophrenia or mood disorders undergoing treatment with various antipsychotic medications, including olanzapine, clozapine, risperidone, and quetiapine. Included were 59 patients allocated to the weight management program and 51 who received usual psychiatric care.

Their findings appear in the Australian and New Zealand Journal of Psychiatry.

The two groups were similar in age and in duration of treatment with their current main antipsychotic drug. Nearly half of the patients were obese, and diabetes, high blood pressure and high cholesterol were common in both groups.

During follow-up, body weight decreased in the exercise group, but increased in the comparison group.

Likewise, subjects in the exercise group saw significant improvements in their blood sugar levels and cholesterol levels. Subjects in the usual care group, by contrast, experienced a worsened of their cholesterol levels.

'The present findings highlight the importance of an ongoing weight management intervention including physical exercise designed specifically for patients on antipsychotic treatment,' Dr Tremblay and his associates conclude. -- REUTERS